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2006 CR 250R Jetting Recommendation

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I just want to get rid of this oil party that keeps happening every time I ride, it’s really quite ridiculous.  We shall see what happens.

How much do you think this pilot change is going to affect it?  I was already down to a 37.5 but I still questioned if it needed to go even smaller.

The needle design is definitely different.  The tip has a different angle cut on it and the bottom portion of the taper is thicker.

The needle and pilot changes are encouraging because both are going the direction I want them to go which is to restrict more fuel, so fingers crossed.

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I like JD's kits.  I have used them on all my bikes since I got back into biking back in about 07 and have been happy with the results.  On my 2 250's I actually did the PWK carb conversion and used JD's needles on both of them for a while until RTV pointed me in the direction of some OEM needles from Yamaha and Kawasaki that I liked better.  I never used the Mikuni carbs on both of my 250's so I am not familiar with their jetting but IMO, you should get good results just by using his instructions to get your initial jetting.  If your experience is anything like mine with his kits, you should be pretty happy with just his baseline jetting settings and then you can fine tune from there.

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Now it won't start.  Not even a little sign.  No fire, no back fire, no nothing.  Choke on, choke off no change.  No throttle, a little throttle no change.

 

I have the red needle on 3rd clip with 32.5 pilot and 400 main all from the kit.

 

- New spark plug

- Spark plug boot seated tightly

- TPS is connected

- Gas feeding to carb

- I remember carefully reassembly the carb correctly

 

I'm scheduled to ride in the morning ..... what am I missing here.

 

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Ok here's the answers you are looking for.
1-ditch that carb, it sucks ass. Buy a PWK or a lectron. You will love it
2-if you don't want to do that I understand. It's a lot of money. I always start my tuning with the pilot jet.
-If you screw it in all the way and it doesn't die. You need a smaller pilot. Same goes the other way. Screw it out all the way and it doesn't rev to the moon. You need a bigger pilot
-then I do the needle, barely hold the throttle open, if it starts reving up (its lean) your needle needs to be dropped down. If it gurgles, (its rich) needle needs to be raised up
-then I do the main, get on a road (try and find a slight uphill road) and click through all your gears. Hold that sucker wide. Then pull the clutch in, hold the kill switch and don't let off the throttle till your stopped and not running. Then pull your plug and see if your rich or lean. Your bike should run perfect. Well for a while until the temperature changes 15 degrees. That carb sucks
-next problem is the splooge and bike not running at all. If you had a crap ton of oil coming out of the pipe. Your right crank seal is probably shot. Change both of them. It's easy, just follow the manual and you should be fine. After that if it still splooges out the pipe, YouTube how a 2 stroke pipe works. There are some good info videos on how the pipe savages. The shape of the cones (where your pipe starts to expand and then goes back to small) has a lot to do with how your bike runs and hits the power. At the first cone, a sonic pulse gets shot back at your engine. It's a negative pulse. Helps suck the air/fuel charge into the cylinder. The 2nd come makes a positive pulse wave and pushes your unburnt fuel back into the cylinder. This is called Scavenging. If your engine is all perfect and still splooges this is the problem. Back pressure plays a role in scavenging to. I had the same problem on my modded 125. Thought the same as you did until I watched the videos. I made a custom silencer, 10 inch inner core. And now I have no splooge. And my bike idles to. Never did that before. Plus it lets the bike rev out more. And pulls stronger everywhere. It blew my mind. I hope this helps

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O and if you like bottom end power, deck the bottom of your jug and lower your port timing. Your bike will be a torque monster. But this does take away from the top end. Good luck bud. Let me know if this helps you

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I put the 37.5 back in and it fired up ..... but doesn't want to idle, I have to hold a little throttle open to keep it running.

Throttle set screw all the way in, which is where it was before.  Which concerns me anyways because I see almost no movement of the slide when I screw it all the way in and back out some.

But regardless it would at least idle before.  This is really aggravating.  I hope I didn't waste $80 on 2 needles.

 

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Now it won't start at all anymore.  I tried 4th clip, nothing 2nd clip, nothing.  I'm about to put the original needle back in and go back to my oil party.  JD is about 2 second away from going in the trash!

 

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Don't throw it in the trash. My best advice is to put the jetting in that the bike would run with before you put the JD kit in. (if your hell bent on riding tomorrow). I didn't read the whole thread again. Then see if the bike will run. 

 

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9 minutes ago, Mike_80 said:

Now it won't start at all anymore.  I tried 4th clip, nothing 2nd clip, nothing.  I'm about to put the original needle back in and go back to my oil party.  JD is about 2 second away from going in the trash!

 

Easy now. I fouled a plug earlier this season too. My jetting was a bit rich until I replaced the float & float needle. If you’re having similar issues set your float but make sure the float needle is working. They do wear out. Mine was original from 2007.

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I went back to original set up and bike STILL won't start.

From rich to lean: Blue #3, Red #3, Blue #2, Red #2

Both pilots are definitely clean.

I'm just really frustrated right now.  Still have to take care of my rear flat and haven't even started on that.

 

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36 minutes ago, Dklassen said:

Easy now. I fouled a plug earlier this season too. My jetting was a bit rich until I replaced the float & float needle. If you’re having similar issues set your float but make sure the float needle is working. They do wear out. Mine was original from 2007.

I have 62.8 hours on this float valve.  When it went out last it was leaking gas, a very slow drip.  I haven’t see any signs of that lately or now.

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10 minutes ago, Keith72 said:

Did you try a fresh spark plug with the jetting that worked previously? 

The one I started with had 2 hours on it.  I put a brand new one in and still couldn’t start it, that was before I got it to fire at all.  I looked at it again after I gave up a little while ago and it looks very clean, just a thin film of gas on it.

C7746690-877A-410B-87E6-9382E0F5D986.jpeg

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15 minutes ago, Keith72 said:

How many turns open on your air screw?

I started with the recommended 1 3/4 then started opening it up for there, even tried closing back down to 1 out.  Went back to my original needle and pilot set up with air screw at 2 1/2.

I feel like there’s something else going on with this bike that I’m missing.  Maybe it doesn’t have anything to do with jetting.  Maybe there was already a problem starting to develop before this.

 

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Verify that you have spark again. Wouldn't be surprised if you have an electrical problem. Broken wire, bad ground.... With your jetting the bike should at least start and run like crap. Wish I could be more helpful. Need to have hands on the bike to figure out the problem.. How do the reeds look? Compression? Air leak?

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